Recruitment and retention in clinical trials of minorities is low, particularly in rural underserved populations. This has slowed progress in addressing racial/ethnic disparities in oral health.
To describe factors associated with successful recruitment, and identify predictors of continued retention of pregnant women attending a community health center into a randomized controlled clinical trial to prevent early childhood caries.
The Mothers and Youth Access (MAYA) Trial recruited women in the second trimester of pregnancy. At baseline, consenting women completed an oral health questionnaire and received a dental exam and oral health counseling. Four months postpartum, women returned with their babies for randomization with follow up at 9-, 12-, 18-, 24-, 30-, and 36-month postpartum visits. To assess predictors of retention, data about respondents’ demographics, and oral health-related knowledge, attitudes, and behaviors were obtained by questionnaire and analyzed by logistic and discrete time-to-event regression analyses.
Of 556 predominantly Mexican-American women recruited at baseline, 195 (35%) were excluded after baseline for not meeting inclusion criteria; 361 (65%) continued to randomization. Factors such as race/ethnicity, annual household income, household composition, oral health-related knowledge and behaviors significantly related to retention until randomization. In multivariable models, women reporting a higher annual household income were less likely to be lost to attrition before randomization (odds ratio = 0.73, 95% confidence interval (CI) 0.60–0.89); while Mexican/Mexican-American women were less likely to be lost beyond randomization (hazard ratio = 0.53, 95% CI 0.26–1.08).
Factors not measured at baseline may have been important in predicting attrition. The MAYA Trial is expected to finish by November 2008; therefore, complete results for total retention may differ from those reported here.
Recruitment and retention efforts for pregnant Hispanic women should place heavy emphasis on culture as ethnicity remained the only borderline significant predictor in post randomization retention.